1. Field of the Invention
This invention in general relates to the field of ultrasonic imaging, and more particularly concerns an improved ultrasonic imaging system that automatically dispenses the proper amount of acoustic coupling fluid as an ultrasonic transducer moves along the object to be scanned.
2. Description of the Prior Art
In recent years ultrasonic imaging has become important in many areas of medical diagnosis, as for example, in obstetrics, cardiology, and the detection of tumors. Generally, in the ultrasonic imaging process, an ultrasonic camera or, what we shall refer to herein as an ultrasonic imaging module, is placed against and/or moved over the surface of the patient's body, or other object the interior of which it is desired to image. U.S. Pat. No. 4,246,791 describes an example of such a module. Generally, in the trade, the term "transducer" is ambiguously applied to the entire ultrasonic "camera" or imaging module, to the piezoelectric element in which electrical energy is transformed into vibrating energy, and also to various portions of the system, depending on the viewpoint. For clarity, in this disclosure we shall refer to the ultrasonic "camera" as an ultrasonic imaging module, and shall use the term "transducer" to designate that portion of the camera that actually vibrates. The piezoelectric element in which the energy is transformed from electrical to vibrational shall be referred to as the "transducer element". Of course, in some instances, the transducer and the transducer element may be one and the same.
In order to obtain a meaningful ultrasonic image it is necessary that the interface between the ultrasonic imaging module and the patient be predictable, repeatable, and conductive to the transmission of the ultrasonic energy with minimal distortion. Generally, an acoustic coupling fluid such as Aquasonic Scan.RTM., Parker Labs, Inc., Orange, N.J. 07050 is applied to the surface of the patient's body to provide the desired interface. In the prior art, the acoustic coupling fluid has been applied by hand, which results in varying amount of the fluid being applied, which may lead to erratic transmission of the ultrasonic energy across the interface. Further, this is messy and time-consuming, and sometimes may not be done for these reasons which results in inefficient coupling of the transducer to the body. Therefore, it would be highly desirable to provide an ultrasonic imaging system that overcomes these problems.